Syringes for administering injections are well known and the various types available on the market are generally quite satisfactory. Further, techniques for using the known syringes are well developed. However, practitioners, specially dental practitioners, encounter certain problems in this regard, sometimes in cases of real necessity, but more and more often as the result of requests made by patients.
It is known that local anaesthetic intended to render insensible a tooth on which the dentist is to operate is more effective when injected directly into porous bone. In the case of the mandible, the porous bone is covered by a hard shell, the osseous cortex, which must be perforated before the needle of the syringe can enter the porous bone.